| /* |
| * MPC5200 General Purpose Timer device driver |
| * |
| * Copyright (c) 2009 Secret Lab Technologies Ltd. |
| * Copyright (c) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License as published by the |
| * Free Software Foundation; either version 2 of the License, or (at your |
| * option) any later version. |
| * |
| * This file is a driver for the the General Purpose Timer (gpt) devices |
| * found on the MPC5200 SoC. Each timer has an IO pin which can be used |
| * for GPIO or can be used to raise interrupts. The timer function can |
| * be used independently from the IO pin, or it can be used to control |
| * output signals or measure input signals. |
| * |
| * This driver supports the GPIO and IRQ controller functions of the GPT |
| * device. Timer functions are not yet supported. |
| * |
| * The timer gpt0 can be used as watchdog (wdt). If the wdt mode is used, |
| * this prevents the use of any gpt0 gpt function (i.e. they will fail with |
| * -EBUSY). Thus, the safety wdt function always has precedence over the gpt |
| * function. If the kernel has been compiled with CONFIG_WATCHDOG_NOWAYOUT, |
| * this means that gpt0 is locked in wdt mode until the next reboot - this |
| * may be a requirement in safety applications. |
| * |
| * To use the GPIO function, the following two properties must be added |
| * to the device tree node for the gpt device (typically in the .dts file |
| * for the board): |
| * gpio-controller; |
| * #gpio-cells = < 2 >; |
| * This driver will register the GPIO pin if it finds the gpio-controller |
| * property in the device tree. |
| * |
| * To use the IRQ controller function, the following two properties must |
| * be added to the device tree node for the gpt device: |
| * interrupt-controller; |
| * #interrupt-cells = < 1 >; |
| * The IRQ controller binding only uses one cell to specify the interrupt, |
| * and the IRQ flags are encoded in the cell. A cell is not used to encode |
| * the IRQ number because the GPT only has a single IRQ source. For flags, |
| * a value of '1' means rising edge sensitive and '2' means falling edge. |
| * |
| * The GPIO and the IRQ controller functions can be used at the same time, |
| * but in this use case the IO line will only work as an input. Trying to |
| * use it as a GPIO output will not work. |
| * |
| * When using the GPIO line as an output, it can either be driven as normal |
| * IO, or it can be an Open Collector (OC) output. At the moment it is the |
| * responsibility of either the bootloader or the platform setup code to set |
| * the output mode. This driver does not change the output mode setting. |
| */ |
| |
| #include <linux/device.h> |
| #include <linux/irq.h> |
| #include <linux/interrupt.h> |
| #include <linux/io.h> |
| #include <linux/list.h> |
| #include <linux/mutex.h> |
| #include <linux/of.h> |
| #include <linux/of_platform.h> |
| #include <linux/of_gpio.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/fs.h> |
| #include <linux/watchdog.h> |
| #include <linux/miscdevice.h> |
| #include <linux/uaccess.h> |
| #include <linux/module.h> |
| #include <asm/div64.h> |
| #include <asm/mpc52xx.h> |
| |
| MODULE_DESCRIPTION("Freescale MPC52xx gpt driver"); |
| MODULE_AUTHOR("Sascha Hauer, Grant Likely, Albrecht Dreß"); |
| MODULE_LICENSE("GPL"); |
| |
| /** |
| * struct mpc52xx_gpt - Private data structure for MPC52xx GPT driver |
| * @dev: pointer to device structure |
| * @regs: virtual address of GPT registers |
| * @lock: spinlock to coordinate between different functions. |
| * @gc: gpio_chip instance structure; used when GPIO is enabled |
| * @irqhost: Pointer to irq_domain instance; used when IRQ mode is supported |
| * @wdt_mode: only relevant for gpt0: bit 0 (MPC52xx_GPT_CAN_WDT) indicates |
| * if the gpt may be used as wdt, bit 1 (MPC52xx_GPT_IS_WDT) indicates |
| * if the timer is actively used as wdt which blocks gpt functions |
| */ |
| struct mpc52xx_gpt_priv { |
| struct list_head list; /* List of all GPT devices */ |
| struct device *dev; |
| struct mpc52xx_gpt __iomem *regs; |
| spinlock_t lock; |
| struct irq_domain *irqhost; |
| u32 ipb_freq; |
| u8 wdt_mode; |
| |
| #if defined(CONFIG_GPIOLIB) |
| struct gpio_chip gc; |
| #endif |
| }; |
| |
| LIST_HEAD(mpc52xx_gpt_list); |
| DEFINE_MUTEX(mpc52xx_gpt_list_mutex); |
| |
| #define MPC52xx_GPT_MODE_MS_MASK (0x07) |
| #define MPC52xx_GPT_MODE_MS_IC (0x01) |
| #define MPC52xx_GPT_MODE_MS_OC (0x02) |
| #define MPC52xx_GPT_MODE_MS_PWM (0x03) |
| #define MPC52xx_GPT_MODE_MS_GPIO (0x04) |
| |
| #define MPC52xx_GPT_MODE_GPIO_MASK (0x30) |
| #define MPC52xx_GPT_MODE_GPIO_OUT_LOW (0x20) |
| #define MPC52xx_GPT_MODE_GPIO_OUT_HIGH (0x30) |
| |
| #define MPC52xx_GPT_MODE_COUNTER_ENABLE (0x1000) |
| #define MPC52xx_GPT_MODE_CONTINUOUS (0x0400) |
| #define MPC52xx_GPT_MODE_OPEN_DRAIN (0x0200) |
| #define MPC52xx_GPT_MODE_IRQ_EN (0x0100) |
| #define MPC52xx_GPT_MODE_WDT_EN (0x8000) |
| |
| #define MPC52xx_GPT_MODE_ICT_MASK (0x030000) |
| #define MPC52xx_GPT_MODE_ICT_RISING (0x010000) |
| #define MPC52xx_GPT_MODE_ICT_FALLING (0x020000) |
| #define MPC52xx_GPT_MODE_ICT_TOGGLE (0x030000) |
| |
| #define MPC52xx_GPT_MODE_WDT_PING (0xa5) |
| |
| #define MPC52xx_GPT_STATUS_IRQMASK (0x000f) |
| |
| #define MPC52xx_GPT_CAN_WDT (1 << 0) |
| #define MPC52xx_GPT_IS_WDT (1 << 1) |
| |
| |
| /* --------------------------------------------------------------------- |
| * Cascaded interrupt controller hooks |
| */ |
| |
| static void mpc52xx_gpt_irq_unmask(struct irq_data *d) |
| { |
| struct mpc52xx_gpt_priv *gpt = irq_data_get_irq_chip_data(d); |
| unsigned long flags; |
| |
| spin_lock_irqsave(&gpt->lock, flags); |
| setbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_IRQ_EN); |
| spin_unlock_irqrestore(&gpt->lock, flags); |
| } |
| |
| static void mpc52xx_gpt_irq_mask(struct irq_data *d) |
| { |
| struct mpc52xx_gpt_priv *gpt = irq_data_get_irq_chip_data(d); |
| unsigned long flags; |
| |
| spin_lock_irqsave(&gpt->lock, flags); |
| clrbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_IRQ_EN); |
| spin_unlock_irqrestore(&gpt->lock, flags); |
| } |
| |
| static void mpc52xx_gpt_irq_ack(struct irq_data *d) |
| { |
| struct mpc52xx_gpt_priv *gpt = irq_data_get_irq_chip_data(d); |
| |
| out_be32(&gpt->regs->status, MPC52xx_GPT_STATUS_IRQMASK); |
| } |
| |
| static int mpc52xx_gpt_irq_set_type(struct irq_data *d, unsigned int flow_type) |
| { |
| struct mpc52xx_gpt_priv *gpt = irq_data_get_irq_chip_data(d); |
| unsigned long flags; |
| u32 reg; |
| |
| dev_dbg(gpt->dev, "%s: virq=%i type=%x\n", __func__, d->irq, flow_type); |
| |
| spin_lock_irqsave(&gpt->lock, flags); |
| reg = in_be32(&gpt->regs->mode) & ~MPC52xx_GPT_MODE_ICT_MASK; |
| if (flow_type & IRQF_TRIGGER_RISING) |
| reg |= MPC52xx_GPT_MODE_ICT_RISING; |
| if (flow_type & IRQF_TRIGGER_FALLING) |
| reg |= MPC52xx_GPT_MODE_ICT_FALLING; |
| out_be32(&gpt->regs->mode, reg); |
| spin_unlock_irqrestore(&gpt->lock, flags); |
| |
| return 0; |
| } |
| |
| static struct irq_chip mpc52xx_gpt_irq_chip = { |
| .name = "MPC52xx GPT", |
| .irq_unmask = mpc52xx_gpt_irq_unmask, |
| .irq_mask = mpc52xx_gpt_irq_mask, |
| .irq_ack = mpc52xx_gpt_irq_ack, |
| .irq_set_type = mpc52xx_gpt_irq_set_type, |
| }; |
| |
| static void mpc52xx_gpt_irq_cascade(struct irq_desc *desc) |
| { |
| struct mpc52xx_gpt_priv *gpt = irq_desc_get_handler_data(desc); |
| int sub_virq; |
| u32 status; |
| |
| status = in_be32(&gpt->regs->status) & MPC52xx_GPT_STATUS_IRQMASK; |
| if (status) { |
| sub_virq = irq_linear_revmap(gpt->irqhost, 0); |
| generic_handle_irq(sub_virq); |
| } |
| } |
| |
| static int mpc52xx_gpt_irq_map(struct irq_domain *h, unsigned int virq, |
| irq_hw_number_t hw) |
| { |
| struct mpc52xx_gpt_priv *gpt = h->host_data; |
| |
| dev_dbg(gpt->dev, "%s: h=%p, virq=%i\n", __func__, h, virq); |
| irq_set_chip_data(virq, gpt); |
| irq_set_chip_and_handler(virq, &mpc52xx_gpt_irq_chip, handle_edge_irq); |
| |
| return 0; |
| } |
| |
| static int mpc52xx_gpt_irq_xlate(struct irq_domain *h, struct device_node *ct, |
| const u32 *intspec, unsigned int intsize, |
| irq_hw_number_t *out_hwirq, |
| unsigned int *out_flags) |
| { |
| struct mpc52xx_gpt_priv *gpt = h->host_data; |
| |
| dev_dbg(gpt->dev, "%s: flags=%i\n", __func__, intspec[0]); |
| |
| if ((intsize < 1) || (intspec[0] > 3)) { |
| dev_err(gpt->dev, "bad irq specifier in %s\n", ct->full_name); |
| return -EINVAL; |
| } |
| |
| *out_hwirq = 0; /* The GPT only has 1 IRQ line */ |
| *out_flags = intspec[0]; |
| |
| return 0; |
| } |
| |
| static const struct irq_domain_ops mpc52xx_gpt_irq_ops = { |
| .map = mpc52xx_gpt_irq_map, |
| .xlate = mpc52xx_gpt_irq_xlate, |
| }; |
| |
| static void |
| mpc52xx_gpt_irq_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node) |
| { |
| int cascade_virq; |
| unsigned long flags; |
| u32 mode; |
| |
| cascade_virq = irq_of_parse_and_map(node, 0); |
| if (!cascade_virq) |
| return; |
| |
| gpt->irqhost = irq_domain_add_linear(node, 1, &mpc52xx_gpt_irq_ops, gpt); |
| if (!gpt->irqhost) { |
| dev_err(gpt->dev, "irq_domain_add_linear() failed\n"); |
| return; |
| } |
| |
| irq_set_handler_data(cascade_virq, gpt); |
| irq_set_chained_handler(cascade_virq, mpc52xx_gpt_irq_cascade); |
| |
| /* If the GPT is currently disabled, then change it to be in Input |
| * Capture mode. If the mode is non-zero, then the pin could be |
| * already in use for something. */ |
| spin_lock_irqsave(&gpt->lock, flags); |
| mode = in_be32(&gpt->regs->mode); |
| if ((mode & MPC52xx_GPT_MODE_MS_MASK) == 0) |
| out_be32(&gpt->regs->mode, mode | MPC52xx_GPT_MODE_MS_IC); |
| spin_unlock_irqrestore(&gpt->lock, flags); |
| |
| dev_dbg(gpt->dev, "%s() complete. virq=%i\n", __func__, cascade_virq); |
| } |
| |
| |
| /* --------------------------------------------------------------------- |
| * GPIOLIB hooks |
| */ |
| #if defined(CONFIG_GPIOLIB) |
| static inline struct mpc52xx_gpt_priv *gc_to_mpc52xx_gpt(struct gpio_chip *gc) |
| { |
| return container_of(gc, struct mpc52xx_gpt_priv, gc); |
| } |
| |
| static int mpc52xx_gpt_gpio_get(struct gpio_chip *gc, unsigned int gpio) |
| { |
| struct mpc52xx_gpt_priv *gpt = gc_to_mpc52xx_gpt(gc); |
| |
| return (in_be32(&gpt->regs->status) >> 8) & 1; |
| } |
| |
| static void |
| mpc52xx_gpt_gpio_set(struct gpio_chip *gc, unsigned int gpio, int v) |
| { |
| struct mpc52xx_gpt_priv *gpt = gc_to_mpc52xx_gpt(gc); |
| unsigned long flags; |
| u32 r; |
| |
| dev_dbg(gpt->dev, "%s: gpio:%d v:%d\n", __func__, gpio, v); |
| r = v ? MPC52xx_GPT_MODE_GPIO_OUT_HIGH : MPC52xx_GPT_MODE_GPIO_OUT_LOW; |
| |
| spin_lock_irqsave(&gpt->lock, flags); |
| clrsetbits_be32(&gpt->regs->mode, MPC52xx_GPT_MODE_GPIO_MASK, r); |
| spin_unlock_irqrestore(&gpt->lock, flags); |
| } |
| |
| static int mpc52xx_gpt_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio) |
| { |
| struct mpc52xx_gpt_priv *gpt = gc_to_mpc52xx_gpt(gc); |
| unsigned long flags; |
| |
| dev_dbg(gpt->dev, "%s: gpio:%d\n", __func__, gpio); |
| |
| spin_lock_irqsave(&gpt->lock, flags); |
| clrbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_GPIO_MASK); |
| spin_unlock_irqrestore(&gpt->lock, flags); |
| |
| return 0; |
| } |
| |
| static int |
| mpc52xx_gpt_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) |
| { |
| mpc52xx_gpt_gpio_set(gc, gpio, val); |
| return 0; |
| } |
| |
| static void |
| mpc52xx_gpt_gpio_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node) |
| { |
| int rc; |
| |
| /* Only setup GPIO if the device tree claims the GPT is |
| * a GPIO controller */ |
| if (!of_find_property(node, "gpio-controller", NULL)) |
| return; |
| |
| gpt->gc.label = kstrdup(node->full_name, GFP_KERNEL); |
| if (!gpt->gc.label) { |
| dev_err(gpt->dev, "out of memory\n"); |
| return; |
| } |
| |
| gpt->gc.ngpio = 1; |
| gpt->gc.direction_input = mpc52xx_gpt_gpio_dir_in; |
| gpt->gc.direction_output = mpc52xx_gpt_gpio_dir_out; |
| gpt->gc.get = mpc52xx_gpt_gpio_get; |
| gpt->gc.set = mpc52xx_gpt_gpio_set; |
| gpt->gc.base = -1; |
| gpt->gc.of_node = node; |
| |
| /* Setup external pin in GPIO mode */ |
| clrsetbits_be32(&gpt->regs->mode, MPC52xx_GPT_MODE_MS_MASK, |
| MPC52xx_GPT_MODE_MS_GPIO); |
| |
| rc = gpiochip_add(&gpt->gc); |
| if (rc) |
| dev_err(gpt->dev, "gpiochip_add() failed; rc=%i\n", rc); |
| |
| dev_dbg(gpt->dev, "%s() complete.\n", __func__); |
| } |
| #else /* defined(CONFIG_GPIOLIB) */ |
| static void |
| mpc52xx_gpt_gpio_setup(struct mpc52xx_gpt_priv *p, struct device_node *np) { } |
| #endif /* defined(CONFIG_GPIOLIB) */ |
| |
| /*********************************************************************** |
| * Timer API |
| */ |
| |
| /** |
| * mpc52xx_gpt_from_irq - Return the GPT device associated with an IRQ number |
| * @irq: irq of timer. |
| */ |
| struct mpc52xx_gpt_priv *mpc52xx_gpt_from_irq(int irq) |
| { |
| struct mpc52xx_gpt_priv *gpt; |
| struct list_head *pos; |
| |
| /* Iterate over the list of timers looking for a matching device */ |
| mutex_lock(&mpc52xx_gpt_list_mutex); |
| list_for_each(pos, &mpc52xx_gpt_list) { |
| gpt = container_of(pos, struct mpc52xx_gpt_priv, list); |
| if (gpt->irqhost && irq == irq_linear_revmap(gpt->irqhost, 0)) { |
| mutex_unlock(&mpc52xx_gpt_list_mutex); |
| return gpt; |
| } |
| } |
| mutex_unlock(&mpc52xx_gpt_list_mutex); |
| |
| return NULL; |
| } |
| EXPORT_SYMBOL(mpc52xx_gpt_from_irq); |
| |
| static int mpc52xx_gpt_do_start(struct mpc52xx_gpt_priv *gpt, u64 period, |
| int continuous, int as_wdt) |
| { |
| u32 clear, set; |
| u64 clocks; |
| u32 prescale; |
| unsigned long flags; |
| |
| clear = MPC52xx_GPT_MODE_MS_MASK | MPC52xx_GPT_MODE_CONTINUOUS; |
| set = MPC52xx_GPT_MODE_MS_GPIO | MPC52xx_GPT_MODE_COUNTER_ENABLE; |
| if (as_wdt) { |
| clear |= MPC52xx_GPT_MODE_IRQ_EN; |
| set |= MPC52xx_GPT_MODE_WDT_EN; |
| } else if (continuous) |
| set |= MPC52xx_GPT_MODE_CONTINUOUS; |
| |
| /* Determine the number of clocks in the requested period. 64 bit |
| * arithmatic is done here to preserve the precision until the value |
| * is scaled back down into the u32 range. Period is in 'ns', bus |
| * frequency is in Hz. */ |
| clocks = period * (u64)gpt->ipb_freq; |
| do_div(clocks, 1000000000); /* Scale it down to ns range */ |
| |
| /* This device cannot handle a clock count greater than 32 bits */ |
| if (clocks > 0xffffffff) |
| return -EINVAL; |
| |
| /* Calculate the prescaler and count values from the clocks value. |
| * 'clocks' is the number of clock ticks in the period. The timer |
| * has 16 bit precision and a 16 bit prescaler. Prescaler is |
| * calculated by integer dividing the clocks by 0x10000 (shifting |
| * down 16 bits) to obtain the smallest possible divisor for clocks |
| * to get a 16 bit count value. |
| * |
| * Note: the prescale register is '1' based, not '0' based. ie. a |
| * value of '1' means divide the clock by one. 0xffff divides the |
| * clock by 0xffff. '0x0000' does not divide by zero, but wraps |
| * around and divides by 0x10000. That is why prescale must be |
| * a u32 variable, not a u16, for this calculation. */ |
| prescale = (clocks >> 16) + 1; |
| do_div(clocks, prescale); |
| if (clocks > 0xffff) { |
| pr_err("calculation error; prescale:%x clocks:%llx\n", |
| prescale, clocks); |
| return -EINVAL; |
| } |
| |
| /* Set and enable the timer, reject an attempt to use a wdt as gpt */ |
| spin_lock_irqsave(&gpt->lock, flags); |
| if (as_wdt) |
| gpt->wdt_mode |= MPC52xx_GPT_IS_WDT; |
| else if ((gpt->wdt_mode & MPC52xx_GPT_IS_WDT) != 0) { |
| spin_unlock_irqrestore(&gpt->lock, flags); |
| return -EBUSY; |
| } |
| out_be32(&gpt->regs->count, prescale << 16 | clocks); |
| clrsetbits_be32(&gpt->regs->mode, clear, set); |
| spin_unlock_irqrestore(&gpt->lock, flags); |
| |
| return 0; |
| } |
| |
| /** |
| * mpc52xx_gpt_start_timer - Set and enable the GPT timer |
| * @gpt: Pointer to gpt private data structure |
| * @period: period of timer in ns; max. ~130s @ 33MHz IPB clock |
| * @continuous: set to 1 to make timer continuous free running |
| * |
| * An interrupt will be generated every time the timer fires |
| */ |
| int mpc52xx_gpt_start_timer(struct mpc52xx_gpt_priv *gpt, u64 period, |
| int continuous) |
| { |
| return mpc52xx_gpt_do_start(gpt, period, continuous, 0); |
| } |
| EXPORT_SYMBOL(mpc52xx_gpt_start_timer); |
| |
| /** |
| * mpc52xx_gpt_stop_timer - Stop a gpt |
| * @gpt: Pointer to gpt private data structure |
| * |
| * Returns an error if attempting to stop a wdt |
| */ |
| int mpc52xx_gpt_stop_timer(struct mpc52xx_gpt_priv *gpt) |
| { |
| unsigned long flags; |
| |
| /* reject the operation if the timer is used as watchdog (gpt 0 only) */ |
| spin_lock_irqsave(&gpt->lock, flags); |
| if ((gpt->wdt_mode & MPC52xx_GPT_IS_WDT) != 0) { |
| spin_unlock_irqrestore(&gpt->lock, flags); |
| return -EBUSY; |
| } |
| |
| clrbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_COUNTER_ENABLE); |
| spin_unlock_irqrestore(&gpt->lock, flags); |
| return 0; |
| } |
| EXPORT_SYMBOL(mpc52xx_gpt_stop_timer); |
| |
| /** |
| * mpc52xx_gpt_timer_period - Read the timer period |
| * @gpt: Pointer to gpt private data structure |
| * |
| * Returns the timer period in ns |
| */ |
| u64 mpc52xx_gpt_timer_period(struct mpc52xx_gpt_priv *gpt) |
| { |
| u64 period; |
| u64 prescale; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&gpt->lock, flags); |
| period = in_be32(&gpt->regs->count); |
| spin_unlock_irqrestore(&gpt->lock, flags); |
| |
| prescale = period >> 16; |
| period &= 0xffff; |
| if (prescale == 0) |
| prescale = 0x10000; |
| period = period * prescale * 1000000000ULL; |
| do_div(period, (u64)gpt->ipb_freq); |
| return period; |
| } |
| EXPORT_SYMBOL(mpc52xx_gpt_timer_period); |
| |
| #if defined(CONFIG_MPC5200_WDT) |
| /*********************************************************************** |
| * Watchdog API for gpt0 |
| */ |
| |
| #define WDT_IDENTITY "mpc52xx watchdog on GPT0" |
| |
| /* wdt_is_active stores whether or not the /dev/watchdog device is opened */ |
| static unsigned long wdt_is_active; |
| |
| /* wdt-capable gpt */ |
| static struct mpc52xx_gpt_priv *mpc52xx_gpt_wdt; |
| |
| /* low-level wdt functions */ |
| static inline void mpc52xx_gpt_wdt_ping(struct mpc52xx_gpt_priv *gpt_wdt) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&gpt_wdt->lock, flags); |
| out_8((u8 *) &gpt_wdt->regs->mode, MPC52xx_GPT_MODE_WDT_PING); |
| spin_unlock_irqrestore(&gpt_wdt->lock, flags); |
| } |
| |
| /* wdt misc device api */ |
| static ssize_t mpc52xx_wdt_write(struct file *file, const char __user *data, |
| size_t len, loff_t *ppos) |
| { |
| struct mpc52xx_gpt_priv *gpt_wdt = file->private_data; |
| mpc52xx_gpt_wdt_ping(gpt_wdt); |
| return 0; |
| } |
| |
| static const struct watchdog_info mpc5200_wdt_info = { |
| .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, |
| .identity = WDT_IDENTITY, |
| }; |
| |
| static long mpc52xx_wdt_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| struct mpc52xx_gpt_priv *gpt_wdt = file->private_data; |
| int __user *data = (int __user *)arg; |
| int timeout; |
| u64 real_timeout; |
| int ret = 0; |
| |
| switch (cmd) { |
| case WDIOC_GETSUPPORT: |
| ret = copy_to_user(data, &mpc5200_wdt_info, |
| sizeof(mpc5200_wdt_info)); |
| if (ret) |
| ret = -EFAULT; |
| break; |
| |
| case WDIOC_GETSTATUS: |
| case WDIOC_GETBOOTSTATUS: |
| ret = put_user(0, data); |
| break; |
| |
| case WDIOC_KEEPALIVE: |
| mpc52xx_gpt_wdt_ping(gpt_wdt); |
| break; |
| |
| case WDIOC_SETTIMEOUT: |
| ret = get_user(timeout, data); |
| if (ret) |
| break; |
| real_timeout = (u64) timeout * 1000000000ULL; |
| ret = mpc52xx_gpt_do_start(gpt_wdt, real_timeout, 0, 1); |
| if (ret) |
| break; |
| /* fall through and return the timeout */ |
| |
| case WDIOC_GETTIMEOUT: |
| /* we need to round here as to avoid e.g. the following |
| * situation: |
| * - timeout requested is 1 second; |
| * - real timeout @33MHz is 999997090ns |
| * - the int divide by 10^9 will return 0. |
| */ |
| real_timeout = |
| mpc52xx_gpt_timer_period(gpt_wdt) + 500000000ULL; |
| do_div(real_timeout, 1000000000ULL); |
| timeout = (int) real_timeout; |
| ret = put_user(timeout, data); |
| break; |
| |
| default: |
| ret = -ENOTTY; |
| } |
| return ret; |
| } |
| |
| static int mpc52xx_wdt_open(struct inode *inode, struct file *file) |
| { |
| int ret; |
| |
| /* sanity check */ |
| if (!mpc52xx_gpt_wdt) |
| return -ENODEV; |
| |
| /* /dev/watchdog can only be opened once */ |
| if (test_and_set_bit(0, &wdt_is_active)) |
| return -EBUSY; |
| |
| /* Set and activate the watchdog with 30 seconds timeout */ |
| ret = mpc52xx_gpt_do_start(mpc52xx_gpt_wdt, 30ULL * 1000000000ULL, |
| 0, 1); |
| if (ret) { |
| clear_bit(0, &wdt_is_active); |
| return ret; |
| } |
| |
| file->private_data = mpc52xx_gpt_wdt; |
| return nonseekable_open(inode, file); |
| } |
| |
| static int mpc52xx_wdt_release(struct inode *inode, struct file *file) |
| { |
| /* note: releasing the wdt in NOWAYOUT-mode does not stop it */ |
| #if !defined(CONFIG_WATCHDOG_NOWAYOUT) |
| struct mpc52xx_gpt_priv *gpt_wdt = file->private_data; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&gpt_wdt->lock, flags); |
| clrbits32(&gpt_wdt->regs->mode, |
| MPC52xx_GPT_MODE_COUNTER_ENABLE | MPC52xx_GPT_MODE_WDT_EN); |
| gpt_wdt->wdt_mode &= ~MPC52xx_GPT_IS_WDT; |
| spin_unlock_irqrestore(&gpt_wdt->lock, flags); |
| #endif |
| clear_bit(0, &wdt_is_active); |
| return 0; |
| } |
| |
| |
| static const struct file_operations mpc52xx_wdt_fops = { |
| .owner = THIS_MODULE, |
| .llseek = no_llseek, |
| .write = mpc52xx_wdt_write, |
| .unlocked_ioctl = mpc52xx_wdt_ioctl, |
| .open = mpc52xx_wdt_open, |
| .release = mpc52xx_wdt_release, |
| }; |
| |
| static struct miscdevice mpc52xx_wdt_miscdev = { |
| .minor = WATCHDOG_MINOR, |
| .name = "watchdog", |
| .fops = &mpc52xx_wdt_fops, |
| }; |
| |
| static int mpc52xx_gpt_wdt_init(void) |
| { |
| int err; |
| |
| /* try to register the watchdog misc device */ |
| err = misc_register(&mpc52xx_wdt_miscdev); |
| if (err) |
| pr_err("%s: cannot register watchdog device\n", WDT_IDENTITY); |
| else |
| pr_info("%s: watchdog device registered\n", WDT_IDENTITY); |
| return err; |
| } |
| |
| static int mpc52xx_gpt_wdt_setup(struct mpc52xx_gpt_priv *gpt, |
| const u32 *period) |
| { |
| u64 real_timeout; |
| |
| /* remember the gpt for the wdt operation */ |
| mpc52xx_gpt_wdt = gpt; |
| |
| /* configure the wdt if the device tree contained a timeout */ |
| if (!period || *period == 0) |
| return 0; |
| |
| real_timeout = (u64) *period * 1000000000ULL; |
| if (mpc52xx_gpt_do_start(gpt, real_timeout, 0, 1)) |
| dev_warn(gpt->dev, "starting as wdt failed\n"); |
| else |
| dev_info(gpt->dev, "watchdog set to %us timeout\n", *period); |
| return 0; |
| } |
| |
| #else |
| |
| static int mpc52xx_gpt_wdt_init(void) |
| { |
| return 0; |
| } |
| |
| static inline int mpc52xx_gpt_wdt_setup(struct mpc52xx_gpt_priv *gpt, |
| const u32 *period) |
| { |
| return 0; |
| } |
| |
| #endif /* CONFIG_MPC5200_WDT */ |
| |
| /* --------------------------------------------------------------------- |
| * of_platform bus binding code |
| */ |
| static int mpc52xx_gpt_probe(struct platform_device *ofdev) |
| { |
| struct mpc52xx_gpt_priv *gpt; |
| |
| gpt = devm_kzalloc(&ofdev->dev, sizeof *gpt, GFP_KERNEL); |
| if (!gpt) |
| return -ENOMEM; |
| |
| spin_lock_init(&gpt->lock); |
| gpt->dev = &ofdev->dev; |
| gpt->ipb_freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node); |
| gpt->regs = of_iomap(ofdev->dev.of_node, 0); |
| if (!gpt->regs) |
| return -ENOMEM; |
| |
| dev_set_drvdata(&ofdev->dev, gpt); |
| |
| mpc52xx_gpt_gpio_setup(gpt, ofdev->dev.of_node); |
| mpc52xx_gpt_irq_setup(gpt, ofdev->dev.of_node); |
| |
| mutex_lock(&mpc52xx_gpt_list_mutex); |
| list_add(&gpt->list, &mpc52xx_gpt_list); |
| mutex_unlock(&mpc52xx_gpt_list_mutex); |
| |
| /* check if this device could be a watchdog */ |
| if (of_get_property(ofdev->dev.of_node, "fsl,has-wdt", NULL) || |
| of_get_property(ofdev->dev.of_node, "has-wdt", NULL)) { |
| const u32 *on_boot_wdt; |
| |
| gpt->wdt_mode = MPC52xx_GPT_CAN_WDT; |
| on_boot_wdt = of_get_property(ofdev->dev.of_node, |
| "fsl,wdt-on-boot", NULL); |
| if (on_boot_wdt) { |
| dev_info(gpt->dev, "used as watchdog\n"); |
| gpt->wdt_mode |= MPC52xx_GPT_IS_WDT; |
| } else |
| dev_info(gpt->dev, "can function as watchdog\n"); |
| mpc52xx_gpt_wdt_setup(gpt, on_boot_wdt); |
| } |
| |
| return 0; |
| } |
| |
| static int mpc52xx_gpt_remove(struct platform_device *ofdev) |
| { |
| return -EBUSY; |
| } |
| |
| static const struct of_device_id mpc52xx_gpt_match[] = { |
| { .compatible = "fsl,mpc5200-gpt", }, |
| |
| /* Depreciated compatible values; don't use for new dts files */ |
| { .compatible = "fsl,mpc5200-gpt-gpio", }, |
| { .compatible = "mpc5200-gpt", }, |
| {} |
| }; |
| |
| static struct platform_driver mpc52xx_gpt_driver = { |
| .driver = { |
| .name = "mpc52xx-gpt", |
| .of_match_table = mpc52xx_gpt_match, |
| }, |
| .probe = mpc52xx_gpt_probe, |
| .remove = mpc52xx_gpt_remove, |
| }; |
| |
| static int __init mpc52xx_gpt_init(void) |
| { |
| return platform_driver_register(&mpc52xx_gpt_driver); |
| } |
| |
| /* Make sure GPIOs and IRQs get set up before anyone tries to use them */ |
| subsys_initcall(mpc52xx_gpt_init); |
| device_initcall(mpc52xx_gpt_wdt_init); |